Sonic tool for activating the flow of particulate material



Feb. 27, 1968 A. G. BODINE 3,370,758

SONIC TOOL FOR ACTIVATING THE FLOW OF' PARTICULATE MATERIAL Filed'Deo.19, 1966 2 Sheets-Sheet l A Z0 a' Z0 216 2z INVENTOR.

A. G. BOBINE 3,370,758

ACTIVATING THE FLOW OF ULATE MATERIAL Feb. 27, 1968 SONIC TOOL. FORPARTIC Filed Dec. 19, 1966 mm. www! QS.. /////7/ United States Patent O3,370,758 SNICA TOOL FOR ACTIVATING THE FLOW 0F PARTICULATE MATERIALAlbert G. Bodine, 7877 Woodley Ave., Van Nuys, Calif. 91406 Filed Dec.19, 1966, Ser. No. 603,040 8 Claims. (Cl. 222-196) vABSTRACT F THEDISCLOSURE A portable sonic tool including an elongated hollow elasticmember in which is contained an orbiting-mass oscillator. Thevibrational output of the oscillator is coupled to the elastic memberand such oscillator rotatably driven by a motor, also contained withinthe elastic member, at a speed such as to cause a resonant vibration ofthe elastic member. The tool forms a self-contained resonant vibrationsystem which when placed on the surface of particulate material to beactivated effectively uidizes such material by causing it to vibraterandomly as a resistive impedance load.

This invention relates to a sonic tool for activating the ilow ofparticulate material and more particularly to such a tool which isresonantly vibrated by -means of an orbiting-mass oscillator. i

In removing particulate material such as grain, granular ores, coal andthe like, from storage containers such as bins, tanks and silos, agravity feed system is generally utilized whereby the particulatematerial is permitted to flow out the bottom of the container. Suchmaterial often assumes a static angle of repose which makes itimpossible to empty the container by gravity feed alone. The removal ofthis material often requires a considerable amount of extra work,involving, for example, manual removal7 the installation of complexhandling equipment such as drag line buckets, or the use of skip-loadtractors to push the material to the outlet opening. To alleviate thisproblem silos having conical or pyramidal bottom portions are oftenutilized and the silo is made relatively tall to provide a hydrostatichead to implement the ow. Tall silos tend to be relatively expensive inconstruction, especially in view of the necessity for providingstructure capable of handling high hydrostatic forces. Further,rectangular silos with pyramidal bottoms have a disadvantage in thatpyra-midal shaped bottoms tend to trap material in the four cornersthereof. Thus, the various measures for overcoming the static repose ofmaterial in storage members, while somewhat eifective in overcoming thisproblem, pose distinct problems in themselves.

VA relatively shallow storage facility which is close to the ground hasdistinct advantages from the pointvof view of economy, stability andease of installation. Iny addition, this type of silo could be movedfrom place to place as required providing maximum utilization of thestorage facility at a relatively low handlingcost.

This invention is also particularly directed to the loading andunloading of barges, which are extreme examples of flat-shapedcontainers with the above mentioned attendant problems.

The device of this invention makes possible the utilization of such asimple shallow storage facility by making use of sonic energy toactivate the particulate material so that it readily ows from thestorage member. The sonic energy is transmitted to the particulatematerial from a self-contained resonant vibration system, the materialforming a resistive impedance load on such system. The resonantvibration system is formed by an elesatichollow enclosure member "ice inwhich is contained an orbiting-mass oscillator. The vibraional output ofthe oscillator is acoustically coupled to the elastic member and theoscillator driven at a rotation frequency such as to cause resonantelastic vibration of the enclosure member. The sonic tool is portableand is set in place on the particulate material, such particulatematerial vibrating randomly and assuming a highly fluid condition inresponse ot the Sonic energy. The sonic energy thus highly lluidizes thegranular material, enabling it to ow freely from the storage member.Such iluidization also thoroughly mixes the granular material andprevents the material from agglomerating.

It has been found most helpful in analyzing the operation of the deviceof this invention to analogize the acoustically vibrating circuitinvolved to an equivalent electrical circuit. This sort of approach toanalysis is well known to those skilled in the art and is described, forexample, in Chapter 2 of Sonics by Hucter and Bolt, published in 1955 byJohn Wiley and Sons. In making such an analogy, force F is equated withelectrical voltage E, velocity of vibration u is equated with electricalcurrent i, mechanical compliance Cm is equated with electricalcapacitance Ce, mass M is equated with electrical inductance L,mechanical resistance (friction) Rm is equated with electricalresistance R, and mechanical impedance Zm is equated with electricalimpedance Ze.

' Thus, it can be shown that if a member is elastically vibrated bymeans of an acoustical sinusoidal force F0 sin wt (w being equal to2ntimes the frequency of vibration), that 1- F0 Slll wt Zm Rm+J wM NCQ-T (l) Where wM is equal L wC'm a resonant condition exists, and theeffective mechanical impedance Zm is-equal to the mechanical resistanceRm, the reactive impedance components wM and wCm cancelling each otherout. Under such a resonant condition, velocity of vibration u is atmaximum, power factor is unity, and energy is most eiciently deliveredto a load to Which'the resonant system may be coupled. y

It is to be noted that in the device of this invention the mass andcompliance for forming the resonantly vibrating system are furnished bythe structural members of such system themselves such that theparticulate material is not incorporated as a reactance in such system.The particulate material under such conditions acts as a resistiveimpedance load which provides no significant reactive components. Thisemployment of apparatus resonance results in a random vibration of theparticles, rather than a lumped coherent vibration such as results fromnonresonant vibrating apparatus, with a considerable vrelative motionoccuring between the separate particles. It is believed that each of theindividual irregular particles when energized by the sonic energy inthis sonic resonant fashion separately vibrates in a random path with arelatively iixed radius of vibration which changes in direction butremains fixed in magnitude. Such random vibration effectively separatesthe particles so that they do not ad! here to each other. The net resultis a uniquely high degree of uidization of the particulate material.

It is also important to note the significance of the attainment of highacoustical Q in the resonant system being driven, to increase theeiciency of the vibration thereof and to provide a maximum amount ofenergy for the flow activation. As for an equivalent electrical circuit,

the Q of an acoustically vibrating circuit is defined as y the sharpnessof resonance thereof and is indicative of the ratio of the energy storedin each vibration cycle to the energy used in each such cycle. Q ismathematicallyV equated to the ratio between M and wRm. Thus,theeifective Q 'of the vibrating circuit can be maximized to make fo'rhighly efficient, high-amplitude vibration by minimizing the effect ofunnecessary friction in the circuit and/ or maximizing the effect ofmassV in such circuit.

In considering the significance of the Iparameters described inconnection with Equation (1), it should be kept in mind that the tofaleffective resistance,.mass, and compliance in the acoustically vibratingcircuit are represented in the equation and that these parameters may bedistributed throughout the system rather than being lumped in any onecomponent or portion thereof.

It is also to be noted that an orbiting mass oscillator may be utilizedin the device of the invention that automatically adjusts its outputfrequency to maintain resonance with changes in the characteristics ofthe load. Thus, in the face of changes in the effective impedancepresented by the load, the system automatically is maintained in optimumresonant operation by virtue of the lock-in characteristics ofapplicants unique orbitingmass oscillator. The orbiting-mass oscillator'automatically changes not only its frequency but its phase angle andtherefore its power factor with changes in the resistive impedance loadto assure optimum efficiency of operation at all times.

It is, therefore, "an object of this Vinvention to Yfacilitate the ow ofparticulate material from a storage member.

It is a further object of this invention to provide vmeans for utilizingsonic lenergy to enable the removal of particulate material from storagemembers.

It is still another object of this invention to 4provide sonic means formore economically handling particulate material.

It is still a further object of this invention to enable the utilizationof simple and economical storage facilities for particulate material.

Other 'objects of this invention will become apparent from the followingdescription taken in connection with the accompanying drawings of which:

FIG. 1 is an elevational view illustrating the utilization of apreferred embodiment of the device ofthe invention to remove particulatematerial from a storage bin;

FIG. 2 is a further View illustrating vthe removal process shown YinFIG. 1 somewhat later in the removal Yoperation;

FIG. 3 is a perspective view with partial cutaway section of a preferredembodiment Vof the device of the invention;

FIG. 4 is a cross-sectional view of an oscillator which may be utilizedin the device of the invention; and

FIG. 5 is a cross-sectional view taken along the Iplane indicated by 5 5in FIG. 4.

Referring now to FIGS. 1 and 2, the utilization of a preferredembodiment of the device of the invention for removing particulatematerial from a storage bin is illustrated. Particulate material 11which may comprise grain is in the process of being removed from storagebin 12 through opening "12a in the bottom of the bin andthe' openingprovided by means of 'sliding door 14. AS can be seen, the material 11aand 11b prior to sonic activation had assumed Va static repose conditionin the bin. Resting on theV surface of'material 11b on the righthandside of the bin vis sonic tool 15.7Sonic tool 1'5 vis lowered intoposition on top of material 11b and 'guided by means of cable 16 rwhichis attached at one end thereof to hook 18 on the tool and at the Votherend thereof to cleat V19 which is attached to vbin The tool effectivelyoats on the surface of the material.

Pulley wheels 20Y and 21 are provided to facilitate the Y manipulationof the cable.

Sonic tool 15, as to be explained in connection with FIG. 3, isresonantly vibrated at a sonic frequency. Sonic energy is coupled to thesurface of particulate material '11b and causes random vibration of suchmaterial in view of the fact thaty such material acts as a resistiveload on the resonant Vibration system. Such 'random vibration of theindividual particles of material 11bV causes a high degree ofYiluidization of such material thereby activating the flow thereof outof bin 12 onto conveyor belt 25. This tiow continues until substatniallyall of the material has been removed from Athe bin. This operation isrepeated to remove material 11a, in thisA instance utilizing cleat 19aand pulley wheels 20a and 21a to guide cable '16.7 Y

As can be seen in FIG. 2 as the particulate material 11b flows out ofthe bin and the repose angle decreases, tool 15 moves downwardly closertoy the bottom Vof the bin, at all times remaining generally near or onthe surface ofthe particulate material. Y Y g Referring now to FIG. 3, apreferred embodiment of the device of the invention is illustrated.Sonic` tool 15 comprises a tubular enclosure member 30 which is closedon both ends by means of caps 30a-and 3 G'b. Tubular enclosure member 30is preferably made of a highly elastic material such as steel, oraluminum alloy. The housing of orbiting-mass oscillator 33vis attachedto fthe .inside of enclosurev30 as, Yfor example, by press fitting. Thisoscillator may be ofthe type to be described in 'connection with FIGS. 4and `5, having an eccentric rotor 36 which is rotatably drivenaround arace formed in the oscillator housing. Rotor 36 is rotatably VdrivenV bymeans of electric motor 40. Electric motor 40 is fitted within tubularmember 30 by means of resilient bushings 42 which vibrationally isolatethe motor from the walls of the enclosure. The drive shaft 40a of themotor is vflexibly coupled to oscillatorvdrive shaft v5 by means ofspline'd coupler member 45. Electrical power is `sjl'lpplied to 'themotor throughvpower cable 47. Y

To assume that the sonic tool in effect floats on the suface "of theparticulate material, a good air pocket should be formed 4therein bysealing vthe ends of tubular enclosure and the enclosure itself made ofas lightweight material fas feasible. Such lightweight construction, ocourse, also facilitates the handling of the unit.

Rotor 36 is rotatably driven by motor at a rota-- tion speed such 'as'to cause resonant vibration of tubular enclosure 30. It is to 'be notedthat the force pattern@ generated Vby means of oscillator 33 is agyratory one,- and this rotary vibratory motion `tends to give the tool'some 'degree of propulsive mobility along the surface of Y theparticulate material so that it effectively moves alongA such surface toefficiently activate the entire area of such surface.

Referring now to FIGS. 4 and 5, the details of an orbiting-massoscillator unit which may be utilized in the device of the Vinventionare illustrated. The oscillator comprises a housing in which iscontained a rotor member 36. Rotor member 36 is rotatably-driven aroundrace 50a formed ,in the housing by means of drive members 51 and l52.Drive members 51 and 52 are attached to oscillator drive shaft 35 andare mounted for rotation on ball bearings '53 and 54, respectively.Drive members l51 vand 52 'have internal gear rings 51av and 52akthereon which engage rotor spur gear rings 36a and 36b,`respec'tively.Rotor 36 further has spur gear 'rings 36C and 36d 'thereon which engageinternal'gea'r rings 50c a'nd 50d attached to housing 50. Gear rings 50cand 50d are Vmounted in the housing on friction springs`50e and 50T,respectively, such springs providing some play in the gear rings tolessen vthe strain on the vgear teeth as the rotor rotates. Y

Thus, as drive Yshaft 35 is rotatably driven, rotor 36 rolls 'around inrace '50a in 'a path which is eccentrically related to the axis of thedrive shaft. This generates a gyratory force pattern in housing Si?.

The device of this invention thus provides highly effective means foractivating the iow of particulate material from a container. This endresult is achieved by generating high-level sonic energy in a portabletool which is placed and maintained on the surface of the particulatematerial so as to cause random sonic vibration thereof, resulting inextremely high fiuidization of such material.

While the device of this invention has been described and illustrated indetail, it is to be clearly understood that this is intended by Way ofillustration and example only and is not to be taken by way oflimitation, the spirit and scope of this invention being limited only bythe terms ofthe following claims.

I claim:

1. A sonic tool for activating the flow of particulate materialcomprising:

a resonant vibration member, said vibration member comprising anelongated elastic hollow enclosure member;

an orbiting-mass oscillator contained within said enclosure member, thevibrational output of said oscillator being coupled to said vibrationmember;

motor means for rotatably driving said oscillator at a rotation speedsuch as to cause resonant sonic vibration of said vibration member as aself-contained resonant vibration system; and

means for maintaining said tool resting at the surface of saidlparticulate material as the ow of said material progresses;

whereby said material is activated by the resonant vibration of saidvibration member with said material presenting a resistive impedanceload on said vibration member.

2. The tool as recited in claim 1 wherein said vibration membercomprises a tubular member closed at both ends thereof.

3. The tool as recited in claim 2 wherein said motor means includes amotor contained within said tubular member and further including meansfor vibrationally isolating said motor from said vibration member.

4. The tool as recited in claim 1 wherein said oscillator is adapted togenerate gyratory vibrations.

5. In combination, a container member, particulate material contained insaid container member, and sonic tool means for activating the flow ofsaid particulate material from said container member comprising:

an elastic hollow enclosure member; mechanical oscillator means forgenerating sonic vibrational energy, said oscillator means beingcontained Within said enclosure member, theA vibrational output of saidoscillator means being coupled to said enclosure member; motor means fordriving said oscillator means at a frequency such as to cause resonantvibration of said enclosure member as a self-contained resonantvibration system; and v means for maintaining said enclosure member onthe surface of said particulate material as the flow of said materialprogresses, said particulate material Vibrating randomly as a resistiveimpedance load on said enclosure member.

6. The combination as recited in claim 5 wherein said oscillator meanscomprises an orbiting-mass oscillator having a gyratory vibrationaloutput.

7. The combination as recited in claim 6 wherein said enclosure memberis in the form of a tube closed at both ends thereof.

8. The combination as recited in claim 7 wherein said oscillator ispress tted within said tube.

References Cited UNITED STATES PATENTS 1,927,075 9/ 1933 Thomas 74-872,174,348 9/ 1939 Damond 222-196 2,761,079 8/ 1956 Giertz-Hedstrom etal. 74-87 2,960,314 11/ 1960 Bodine 259-72 X 3,166,772 1/ 1965 Bodine74-87 X 3,256,695 6/1966 Bodine.

3,264,887 8/ 1966 Holmes 74-87 3,299,722 1/1967 Bodine 74-87 3,308,6713/ 1967 Bodine 74-87 WALTER SOBIN, Primary Examiner.

